Process for producing tissue products
View Patent ↗Tissue products are disclosed containing an additive composition. The additive composition, for instance, comprises an aqueous dispersion containing an alpha-olefin polymer, an ethylene-carboxylic acid copolymer, or mixtures thereof. The alpha-olefin polymer may comprise an interpolymer of ethylene and octene, while the ethylene-carboxylic acid copolymer may comprise ethylene-acrylic acid copolymer. The additive composition may also contain a dispersing agent, such as a fatty acid. The additive composition may be incorporated into the tissue web as the web is being formed. Alternatively, the additive composition may be topically applied to the web in a post processing operation. For instance, in one embodiment, the additive composition may be applied to the web as a creping adhesive during a creping operation.
1. A process for producing a tissue product comprising:
forming a tissue web from an aqueous suspension of fibers;
passing the tissue web while still wet over a vacuum device while being conveyed in between a permeable structured fabric and a permeable de-watering fabric, the de-watering fabric being positioned adjacent to the vacuum device;
applying a force against the permeable structured fabric while the tissue web passes over the vacuum device for de-watering the tissue web;
conveying the web over at least one drying device for drying the tissue web; and
applying an additive composition to at least one side of the tissue web during the process, the additive composition comprising an aqueous dispersion containing a non-fibrous alpha-olefin interpolymer of ethylene or propylene and at least one comonomer, each comonomer being selected from the group consisting of octene, heptene, hexene, decene, and dodecene; the non-fibrous alpha-olefin interpolymer having an average volumetric particle size in the aqueous dispersion of less than about 5 microns, and wherein the tissue product has a bulk of greater than about 3 cc/g after the additive composition has been applied.
2. A process as defined in claim 1 , wherein as the tissue web passes over the vacuum device, air flows through the permeable structured fabric, then through the tissue web, then through the permeable de-watering fabric and into the vacuum device.
3. A process as defined in claim 1 , wherein the drying device comprises a Yankee dryer.
4. A process as defined in claim 1 , wherein the vacuum device comprises a vacuum roll or a vacuum box.
5. A process as defined in claim 1 , wherein the permeable de-watering fabric comprises a felt.
6. A process as defined in claim 1 , wherein the force applied against the permeable structured fabric is produced by a hood or a belt press.
7. A process as defined in claim 1 , wherein the additive composition comprises an alpha-olefin interpolymer of ethylene.
8. A process as defined in claim 1 , wherein the additive composition comprises a mixture of the alpha-olefin polymer and an ethylene-carboxylic acid copolymer.
9. A process as defined in claim 1 , wherein the additive composition is applied to the tissue web after the tissue web passes over the vacuum device.
10. A process as defined in claim 1 , wherein the tissue web is conveyed over a first drying device and a second drying device, the additive composition being applied in between the first drying device and the second drying device.
11. A process as defined in claim 1 , wherein the tissue web is conveyed over a first drying device and a second drying device, the first drying device comprising a rotating drying cylinder, the second drying device comprising a rotating drying cylinder and wherein the additive composition is applied to at least one of the drying devices for transfer onto the tissue web.
12. A process as defined in claim 11 , wherein the second drying device comprises a Yankee dryer and wherein the tissue web is creped from the Yankee dryer.